Latch trip thermal circuit controller



Jan. 7, 1964 r B. R. wANLAss 3,117,204

LATCH TRIP THERMAL CIRCUIT CONTROLLER Filed Nov. 25, 1960 fimm ,IN VEN TOR United States Patent 3,117,204 LATQH TRIP THERMAL CHRQUHT CONTRQLLERBert R. Wanlass, Warren, Mich, assignor to General Motors Corporation,Detroit, Mich, a corporation of Delaware Filed Nov. 25, 16!'l, Ser. No.71,693 Claims. (Cl. 200-l16 This invention relates to a circuitcontroller and more particularly to a circuit controller including meansfor maintm'ning the controller in a closed position for a predeterminedperiod of time and then automatically returning the controller to anopen position.

The controller of this invention is particularly useful for the remotecontrol of power actuated members which are movable between open andclosed positions. Once the controller is initially closed, it willremain in closed position for a predetermined period of time suflicientto permit the power actuated member to be moved between its open andclosed positions and will then automatically open to de-energize thepower actuating means. The means for maintaining the controller in aclosed position can be overridden at any time desired by the operator soas to provide for movement of the power actuated member to a positionintermediate its terminal positions.

In the preferred embodiment of the invention, the controller comprises adouble-pole, double-throw switch which includes bi-metallic detentmeans. The bimetallic detent means are automatically engageable with theswitch actuator upon closure of the switch to hold the actuator in aposition to maintain the switch contacts in a closed position until thebi-metallic means has been sufficiently heated so as to move out ofengagement with the actuator and allow the actuator to return to neutralposition to open the switch.

The primary object of this invention is to provide a new and improvedcircuit controller. Another object of this invention is to provide acircuit controller which includes n cans for maintaining the controllerin a closed position for a predetermined period of time. A furtherobject of this invention is to provide a new and improved circuitcontroller which includes means for maintaining the controller in aclosed position for a predetermined eriod of time and for automaticallyopening the controller upon the expiration of this period of time. Yetanother object of this invention is to provide a new and improveddouble-pole double-throw type switch which includes bi-metallic detentmeans for maintaining the switch in a closed position once the switchactuator has been initially moved to close the contacts of the switch.

These and other objects of this invention will be readily apparent fromthe following specification and drawings wherein:

FIGURE 1 is a sectional view of a circuit controller according to thisinvention, with the controller being shown in open position;

FIGURE 2 is a sectional view taken generally on the plane indicated byline 2-2 of FIGURE 1;

FIGURE 3 is a sectional view taken generally along the plane indicatedby line 33 of FIGURE 1;

FIGURE 4 is a view similar to FIGURE 1 showing the controller in aclosed position; and

FIGURE 5 is a sectional view taken generally along the plane indicatedby line 55 of FIGURE 1.

Referring now to the drawings, the controller includes a housing ll} ofgenerally rectangular shape and having a pair of laterally extendingmounting flanges 12, one at each end thereof. The upper opening 14 ofhousing is defined by a continuous laterally inwardly extending flange16 which acts as a locating means for the switch actuator in the openand closed positions thereof, as will be further described. The loweropening 18 3,li7,2fl4 Patented Jan. 7, 1954 of housing Jill is closed bya switch base plate 20 of insulating material. Oppositely disposedspring arms 22 mount contact buttons 24 at the free ends thereof, withspring arms 22 being secured to the base 20 by contact rivets 26. Acircular spring seat 25 and the base portion of a generally U-shapedbi-metallic detent member 30 are secured to the base plate 20 by acontact rivet 34 which provides the center hot lead for the controller.

The base plate 20 is secured with opening 18 by providing a pair ofupwardly extending slots 36, FIGURES l, 3 and 4 in each side of thehousing 10, generally opposite the contacts 24, with slots 36 beingapertured at 38, FIGURE 3, to receive the tangs 40 of angular lockingmembers 42 which are received within angle slots 44 provided in the baseplate 26 and lateral flanges as thereof, the latter fitting within slots36. Base plate 20 further includes a lateral flange 48 intermediate eachpair of flanges 46 which is received within a slot 50 provided in eachside wall of the housing 10. Flanges 43 are slotted at 52 to pivotallyand slidably receive a pair of laterally extending lugs 54 on anactuator member 56 of insulating material. An actuating button 58-includes a central tapered rivet 649 which is received within acomplementary shaped opening in member 56 and secured thereto by headingover the end of the rivet 6% within a shouldered bore 62 of the member56. Button 58 includes laterally extending flanges 64 at each endthereof which engage the end portions of flange 16 of housing it? in theopen or neutral position of the controller to locate member 56 andbutton 53 as shown in FIGURE 1, with flanges 64 and the end portions offlange 16 being held in engagement with each other by a coil torsionspring 66 which seats on the spring seat 3% and on the shoulder 68, FIG-URE 2, of bore 62.

Member 56 further includes end box sections 70 which open to button 58and extend from each side of the central portion 71 of the member. Aportion '72 of the bottom wall of each box section is cut away to allowpassage of the legs 74 of member 3% therethrough. A slot 76 extendsthrough the bottom Wall and a portion of the end wall of each boxsection 70, with each slot including an enlarged circular portion 78 forgrippingly receiving a contact button till. Each button St) iselectrically connected to a leg 74' of the member 3% by means of wireshaving one end thereof secured to the button and the other end thereofsecured to a shouldered portion 82 at the free end of each leg. Buttons8% are adapted to engage the buttons 24 to close the controller.

When the switch is in an open or neutral position as shown in FIGURE 1,the shouldered portions 82 of the legs 74 of member 3%] slidably engageor grip the generally vertically extending walls 84 of the centralportion 71 of member 56. When it is desired to close the switch, theoperator engages the button 53 so as to depress one end of this button.Assuming that the left-hand end is depressed, the button 58 and member56 will both pivot and slide as a unit relative to base plate 20 as lugs54 move within slots 52 and spring 66 is compressed, as shown in FIGURE4, so that the shouldered portion 82 of the left-hand leg 74 of member30 will engage over the left-hand upper corner or shoulder of portion 71of member 56 to thereby maintain the left-hand contacts and 24 in aclosed position despite release of the button $8 by the operator. Theengagement of the righthand end flange 64- of button 58 with theright-hand end portion of the flange l6 maintains this end of the'buttonin its position as shown against the action of spring 66. Upon closureof the left-hand contacts 80 and 24, a current path will be completedfrom the hot lead 34, through the left-hand leg 74 of member 30, andacross the contacts 80 and 24 to the left-hand contact 26 by means ofthe spring arm 22. After a predetermined period of time,

the left-hand leg 74 of the member 36 will be suffieiently heated sothat it will shift or bend slightly to the left relative to the base ofmember Ed) so as to move outwardly of the left hand upper corner orshoulder of portion '71 whereupon the spring 66 will instantaneouslyreturn the member 56 and button 58 to their position as shown in FIGURE1 to thereby break the circuit across the contacts Sc and 2d and openthe controller.

It will be appreciated that closure of the right-hand set of contacts 80and 24 will operate in a like manner to maintain the controller in aclosed position for a predetermined period of time and then open thecontroller.

Upon reference to FIGURES 1 and 4 of the drawings, it will be noted thatwhen the button 53 is depressed to close the contacts 53 and 24, thelugs 54 move down Wardly within slots 52 and pivot relative theretoagainst the action of spring 66 so that the actuating button 58 andactuator 56 both pivot and slide as a unit relative to the base 2%)until a corner or shoulder of portion 71 moves into engagement with ashouldered portion 82 of one of the legs 74. This is another feature ofthe subject circuit controller.

Thus, this invention provides a new and improved circuit controllerwhich includes means for maintaining the controller in a closed positionfor a predetermined period of time and then automatically returning thecontroller to an open position.

What is claimed is:

1. A circuit controller comprising, in combination, a base membermounting a. first contact, an actuator member mounted on said basemember for movement between neutral and operating positions with respectthereto, said actuator member including a lower wall provided with anaperture therein and a slot opening to said aperture, a second contactgripped between the edges of said slot and adapted to be closed to saidfirst contact in the operating position of said actuator, means on saidactuator member providing a surface terminating in an abrupt shoulder,and a bimetallic member mounted on said base member and electricallyconnected to said second contact, said bimetallic member projectingthrough said aperture and including shoulder means normally biased intoengagement with said surface in the neutral position of said actuatormember and adapted to move along said surface into engagement with saidactuator member shoulder when said actuator member is moved to saidoperating position thereof to maintain said actuating member in saidoperating position for a predetermined period of time.

2. A circuit controller comprising, in combination, a base membermounting a first contact, an actuator member mounted on said base memberfor movement between neutral and operating positions with respectthereto, said actuator member including a generally box-like structurehaving a pair of side walls and a lower wall provided with an aperturetherein and a slot opening to said aperture, a second contact grippedbetween the edges of said slot and adapted to be closed to said firstcontact in the operating position of said actuator, a bimetallic membermounted on said base member and projecting through said aperture, saidbimetallic member being electrically connected to said second contactand including shoulder means normally biased into engagement with one ofsaid side walls in the neutral position of said actuator memher, saidshoulder means being adapted to move along said one of said side wallsand into engagement with the upper edge thereof when said actuatormember is moved to said operating position thereof to maintain saidactuating member in said operating position for a predetermined periodof time.

3. A circuit controller comprising, in combination, a base membermounting spaced first contacts, an actuator member mounted on said basemember for movement between neutral and opposite operating positionswith respect thereto, said actuator member including a pair of generallybox-like structures, each of said structures including a pair ofoppositely disposed side Walls and an intermediate lower wall providedwith an aperture therein and a slot opening to said aperture, a secondcontact gripped between the edges of each slot and adapted to be closedto a respective first contact in one of the operating positions of saidactuator, a generally U-shaped bimetallic member mounted on said basemember, each leg thereof projecting through one of said apertures andbeing electrically connected to one of said second contacts, shouldermeans on each said leg normally slidably engaging one of said side Wallsin the neutral position of said actuator member, one of said shouldermeans moving along a respective one of said side walls into engagementwith the upper edge thereof when said actuator member is moved to one ofsaid operating positions thereof to maintain said actuating member insaid one of said operating positions for a predetermined period of time.

4. A circuit controller comprising, in combination, a base membermounting spaced first contacts, an actuator member mounted on said basemember for movement between neutral and operating positions with respectthereto, spaced second contacts mounted on said actuator member, eachadapted to be closed to a respective first contact in the operatingposition of said actuator member, said actuator member including acentral portion having oppositely disposed spaced surfaces, eachterminating in an abrupt shoulder, a generally U-shaped bimetallicmember having its base portion secured to said base member andenveloping said central portion, each leg of said bimetallic memberbeing electrically connected to one of said second contacts andincluding shoulder means, each being normally biased into engagementwith a respective surface in the neutral position of said actuatormember, movement of said actuator member to said operating positionthereof moving one of said surfaces relative to a respective one of saidlegs to move one of said actuator member shoulder means into engagementwith a respective one of said bimetallic member shoulder means, each legof said bimetallic member being in the current path to a respectivesecond contact whereby closure of a pair of said first and secondcontacts will cause the one leg respective to the closed second contactto be heated and to flex relative to its respective surface after apredetermined period of time to move the one shoulder of said one legout of engagement with said one actuator member shoulder and allow saidactuator member to return to neutral position.

5. A circuit controller comprising, in combination, a base membermounting a first contact, an actuator member mounted on said base memberfor movement between neutral and operating positions with respectthereto, said actuator member including a box portion having a lowerwall provided with an aperture therein, a second contact mounted on saidlower wall and adapted to be closed to said first contact in theoperating position of said actuator member, said actuator memberincluding a surface terminating in an abrupt shoulder within said boxportion, and a bimetallic member mounted on said base member andelectrically connected to said second contact, said bimetallic memberprojecting through said aperture and including shoulder means normallybiased into engagement with said surface in the neutral position of saidactuator member, movement of said actuator member to said operatingposition thereof moving said surface relative to said bimetallicshoulder to move said actuator member shoulder into engagement with saidbimetallic member shoulder, said bimetallic member being in the currentpath to said second contact and maintaining said actuator member in saidoperating position for a predetermined period of time until saidbimetallic member becomes heated to an extent to move said shoulderthereof out of engagement with said actuator member shoulder and allowsaid actuator member to return to said neutral position thereof.

References Cited in the file of this patent UNITED STATES PATENTS 6Schwend et a1. Apr. 10, 1951 Toth Nov. 24, 1953 Straub et a1 Aug. 10,1954 Allen Sept. 17, 1957 Ellenberger Feb. 25, 1958 Brown Aug. 28, 1962FOREIGN PATENTS France Apr. 17, 1961

1. A CIRCUIT CONTROLLER COMPRISING, IN COMBINATION, A BASE MEMBER MOUNTING A FIRST CONTACT, AN ACTUATOR MEMBER MOUNTED ON SAID BASE MEMBER FOR MOVEMENT BETWEEN NEUTRAL AND OPERATING POSITIONS WITH RESPECT THERETO, SAID ACTUATOR MEMBER INCLUDING A LOWER WALL PROVIDED WITH AN APERTURE THEREIN AND A SLOT OPENING TO SAID APERTURE, A SECOND CONTACT GRIPPED BETWEEN THE EDGES OF SAID SLOT AND ADAPTED TO BE CLOSED TO SAID FIRST CONTACT IN THE OPERATING POSITION OF SAID ACTUATOR, MEANS ON SAID ACTUATOR MEMBER PROVIDING A SURFACE TERMINATING IN AN ABRUPT SHOULDER, AND A BIMETALLIC MEMBER MOUNTED ON SAID BASE MEMBER AND ELECTRICALLY CONNECTED TO SAID SECOND CONTACT, SAID BIMETALLIC MEMBER PROJECTING THROUGH SAID APERTURE AND INCLUDING SHOULDER MEANS NORMALLY BIASED INTO ENGAGEMENT WITH SAID SURFACE IN THE NEUTRAL POSITION OF SAID ACTUATOR MEMBER AND ADAPTED TO MOVE ALONG SAID SURFACE INTO ENGAGEMENT WITH SAID ACTUATOR MEMBER SHOULDER WHEN SAID ACTUATOR MEMBER IS MOVED TO SAID OPERATING POSITION THEREOF TO MAINTAIN SAID ACTUATING MEMBER IN SAID OPERATING POSITION FOR A PREDETERMINED PERIOD OF TIME. 